The Americans with Disabilities Act requires buses and other urban transit vehicles to display route information and other information in an easily readable format. For example, in addition to the route number the vehicle may be provided with signage which identifies the general direction of movement of the vehicle, i.e., downtown, west end, etc. One of the more popular signage types that is utilized on urban transit vehicles for the foregoing purposes comprises LED (light emitting diode) displays.
LED signage is popular because it provides a high contrast image which can be read and understood by persons with highly impaired vision. Because LED signs are entirely electronic the information displayed thereon can be changed virtually instantly, for example, if the vehicle is assigned to a different route. Another advantage in the use of LED signage comprises the fact that the same sign can be used to sequentially display a variety of messages.
One problem that has been encountered in utilization of LED signage on urban transit vehicles involves degradation of the image displayed by the sign due to sunlight and other sources of bright light. Thus, when a LED sign is used in the presence of sunlight or other bright light, the contrast normally associated with a LED sign can be reduced to the point that the sign is hard to read. To overcome this problem LED signs have been provided with covers including louvers which shield the light emitting diodes thereof from excessive light.
In accordance with the present invention, a LED sign comprises a rectangular array of individual light emitting diodes. A cover having dimensions corresponding to those of the rectangular array is positioned in front of the light emitting diodes. A cover is provided with closely spaced, parallel, horizontally disposed slots which expose substantially the entirety of the array of light emitting diodes. Each of the slots is provided with a louver which shields the light emitting diodes from bright light emanating from the sun or any other source. The louvers prevent degradation of the image vented by the LED sign due to impingement of excessive light on the light emitting diodes.
In accordance with more specific aspects of the invention, a LED sign cover comprises a stainless steel sheet which is laser cut to define a relatively long first cut line and two relatively short second cut lines which extend angularly from the opposite ends of the first cut line. Following the cutting step the portion of the stainless steel sheet extending between the two second cut lines is bent relative to the plane of the stainless steel sheet. Bending of the portion of the stainless steel plate extending between the two second cut lines simultaneously forms both an aperture through the stainless steel sheet and a louver extending adjacent to the aperture for shielding the light emitting diode of the LED sign from excessive light.